Abstract This Phase I application aims to determine the feasibility of using lipid enhanced nanosensor (LENS) arrays for smart-phone based detection of lead (Pb2+) and mercury (Hg2+) in drinking water at concentrations above FDA allowable levels. LENS arrays are composed of fluid lipid multilayer diffraction gratings on surfaces. The fluid nature of these arrays has two advantages (1) reagents can be included within the grating volume, and (2) changes in the grating nanostructure upon analyte binding results in an optical readout signal. Three aims must be achieved before proceeding with a Phase II project. First, the sensors must be adapted for selective detection of lead and mercury in a laboratory setting. This will be done by functionalizing the sensor elements with nucleotide sequences known to bind lead and mercury ions. The sensitivity and selectivity of the individual sensor elements will be determined. These elements will then be integrated into arrays composed of different lipid formulations using nanointaglio printing, and selectivity for the analytes at concentrations above FDA allowable levels will be obtained by using an optical nose approach. In order to achieve portability and affordability, a smart-phone attachment will be developed that makes use of the light source camera for detection. The attachment will require a sample volume of one drop (i.e. less than 10 microliters). Finally, the LENS arrays will be tested on real-world water samples spiked with the ions of interest. Our ultimate goal is to produce an affordable general purpose smart-phone attachment and specific cartridges for detection of analytes of interest to the consumer. Successful achievement of the aims of this proposal will demonstrate the technical feasibility of using LENS arrays for detection of lead and mercury in drinking water. As the LENS array technology is potentially scalable, there is potential for multiplexed detection of thousands of analytes from a single drop.